Engine Swap

[rwoodysurplus]

yes you are right--GOOD CATCH~!

going to try that ...pushers suck air from the side

why not the rear????

A simple definition of aerodynamics is the study of the flow of air
around and through a vehicle, primarily if it is in motion. To
understand this flow, you can visualize a car moving through the air.
As we all know, it takes some energy to move the car through the air,
and this energy is used to overcome a force called Drag.

Drag, in vehicle aerodynamics, is comprised primarily of two forces.
Frontal pressure is caused by the air attempting to flow around the
front of the car. As millions of air molecules approach the front
grill of the car, they begin to compress, and in doing so raise the
air pressure in front of the car. At the same time, the air molecules
travelling along the sides of the car are at atmospheric pressure, a
lower pressure compared to the molecules at the front of the car.

Just like an air tank, if the valve to the lower pressure atmosphere
outside the tank is opened, the air molecules will naturally flow to
the lower pressure area, eventually equalizing the pressure inside and
outside the tank. The same rules apply to cars. The compressed
molecules of air naturally seek a way out of the high pressure zone in
front of the car, and they find it around the sides, top and bottom of
the car. See the diagram below.

Diagram of 'Front Pressure'

Rear vacuum (a non-technical term, but very descriptive) is caused by
the "hole" left in the air as the car passes through it. To visualize
this, imagine a bus driving down a road. The blocky shape of the bus
punches a big hole in the air, with the air rushing around the body,
as mentioned above. At speeds above a crawl, the space directly behind
the bus is "empty" or like a vacuum. This empty area is a result of
the air molecules not being able to fill the hole as quickly as the
bus can make it. The air molecules attempt to fill in to this area,
but the bus is always one step ahead, and as a result, a continuous
vacuum sucks in the opposite direction of the bus. This inability to
fill the hole left by the bus is technically called Flow detachment.
See the diagram below.

Diagram of 'Rear Vacuum'

Flow detachment applies only to the "rear vacuum" portion of the drag
equation, and it is really about giving the air molecules time to
follow the contours of a car's bodywork, and to fill the hole left by
the vehicle, it's tires, it's suspension and protrusions (ie. mirrors,
roll bars). If you have witnessed the Le Mans race cars, you will have
seen how the tails of these cars tend to extend well back of the rear
wheels, and narrow when viewed from the side or top. This extra
bodywork allows the air molecules to converge back into the vaccum
smoothly along the body into the hole left by the car's cockpit, and
front area, instead of having to suddenly fill a large empty space.

The reason keeping flow attachment is so important is that the force
created by the vacuum far exceeds that created by frontal pressure,
and this can be attributed to the Turbulence created by the detachment.

Turbulence generally affects the "rear vacuum" portion of the drag
equation, but if we look at a protrusion from the race car such as a
mirror, we see a compounding effect. For instance, the air flow
detaches from the flat side of the mirror, which of course faces
toward the back of the car. The turbulence created by this detachment
can then affect the air flow to parts of the car which lie behind the
mirror. Intake ducts, for instance, function best when the air
entering them flows smoothly. Therefore, the entire length of the car
really needs to be optimized (within reason) to provide the least
amount of turbulence at high speed. See diagram below (Light green
indicates a vacuum-type area behind mirror):

Diagram of turbulence behind mirror

open for discussion!..the test will be at 70 mph on the road.
i do have another fan and will make the rad and intercoler swing and
bumper swing for easy access for repairs.


--- In WanderlodgeForum@yahoogroups.com, "Chuck Wheeler"
wrote:
>
> I'm sure you have thought of this, but the picture of the installed
Cummins
> has a fan that would try to pull air in from the rear. There is a low
> pressure area behind a moving vehicle that would cause the natural
flow to
> be the other way. Are you going to change the fan?
>
> - Chuck Wheeler-
> 1982 FC 31SB Fort Worth TX
>
>
> _____
>
> From: WanderlodgeForum@yahoogroups.com
> [mailto:WanderlodgeForum@yahoogroups.com] On Behalf Of rwoodysurplus
> Sent: Tuesday, December 16, 2008 8:04 PM
> To: WanderlodgeForum@yahoogroups.com
> Subject: [WanderlodgeForum] Re: Engine swap
>
>
>
> HEY GUYS,
>
> sure been working hard to get this engine in..thanks for all the help
> with the BMC info. you can see the pic here as its easier for me to
> post them.
>
> http://www.wanderlo
> <http://www.wanderlodgeownersgroup.com/fo...php?t=2063>
> dgeownersgroup.com/forums/showthread.php?t=2063
>
> woody
> 90 sp
> Bertha conversion
> --- In WanderlodgeForum@
> yahoogroups.com, "Richard Gideon"
> wrote:
> >
> > Hi Hank: Woody's 8.3 Cummins transplant from the donor firetruck is
> > rated at 330hp...and the Cummins will eliminate the diesel smoke to
> > some extent. And additionally Woody likes the Allison 3060
> > Transmission.
> >
> > Enjoy the Harbor Bridge one New Years,
> >
> > Happy New Year
> > Dick Gideon
> > 1989 35FC
> > Rolla, MO
> >
> > --- In WanderlodgeForum@
> yahoogroups.com, "Henry Jay Hannigan"
> > wrote:
> > >
> > > WHY swap a 300hp turbo for a 300hp turbo??? am I missing
> > something??
> > > Seems a 400hp turbo would make more sense for all that work, but
> > then
> > > what do I know?? Not much. I imagine Randy knows what he is
> > > doing.....Cought my eye because I have a 90 SP that could use a
> > little
> > > more ZIP on the hills...
> > >
> > > Getting ready for News Years at the Sydney Bridge....
> > > Regards,
> > > Hank & Naty
> > > 90SP36..tucked away in Vegas
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > --- In WanderlodgeForum@
> yahoogroups.com, "Ernest Ekberg"
> > > wrote:
> > > >
> > > > Randy Dupree and his buddy Woody have taken on a major project.
> > Today
> > > > they began an engine and tranny transplant on Woody's 1990
> > Bluebird
> > > > Wanderlodge SP. The original 300hp Turbo CAT 3208 and ZF tranny
> > are
> > > > being swapped out for a 300hp Turbo Cummins 8.3 and 6 speed
> > Allison
> > > > trannny. Work began this morning at 1030am and by 3pm they had
> > the
> > > > engine and tranny out. It would have been out earlier if they
> > hadn't
> > > > stopped to argue how best to do it. This project will require
> > serious
> > > > fabrication including new designs for exhaust, motor mounts,
> > radiator
> > > > mounting etc to accomodate an engine that is 8 inches longer than
> > the
> > > > original.
> > > > More information and photos as soon as I receive them.
> > > > Ernie- 83PT40 in Texas-same old 6v92
> > > >
> > >
> >
>